Establishing full-duplex audio over an asynchronous bluetooth link

Abstract

A method to establish a full-duplex audio connection over an asynchronous Bluetooth link between an audio terminal and a wireless audio device exchanges supported service classes and codecs between the audio terminal and the wireless audio device, negotiates a service class and a codec that are common to the audio terminal and the wireless audio device, and establishes an asynchronous audio connection between the audio terminal and the wireless audio device using the common service class and the codec. The audio connection established can depend on the software application desiring the audio connection plus the available service classes and codecs at the audio terminal and wireless audio device. For non-internet protocol (non-IP) audio applications, an ACL using AVDTP may be selected; for IP audio applications, an ACL using BNEP may be selected. Both AVDTP and BNEP can use codecs that support wide bandwidth audio.

1. A method for an audio terminal to establish a full-duplex audio connection over an asynchronous Bluetooth link with a wireless audio device comprising:
 exchanging supported service classes and codecs between the audio terminal and the wireless audio device; 
 negotiating a service class and a codec that are common to the audio terminal and the wireless audio device based on the supported service classes and codecs; and 
 establishing an asynchronous audio connection between the audio terminal and the wireless audio device using the service class and the codec. 
 
     
     
       2. The method according to  claim 1  wherein the exchanging supported service classes and codecs comprises:
 transmitting an audio gateway service record from the audio terminal; and 
 receiving a hand-free unit service record from the wireless audio device. 
 
     
     
       3. The method according to  claim 1  wherein the exchanging supported service classes and codecs comprises:
 receiving a transport service class identifier and a codec identifier. 
 
     
     
       4. The method according to  claim 3  wherein the negotiating comprises:
 sending an acknowledgement message to the wireless audio device, if the transport service class identifier corresponds to an audio terminal service class available at the audio terminal and the codec identifier corresponds to an audio terminal codec available at the audio terminal. 
 
     
     
       5. The method according to  claim 3  further comprising:
 sending an error message to the wireless audio device, if the transport service class identifier fails to correspond to an audio terminal service class available at the audio terminal; and 
 re-performing the exchanging step. 
 
     
     
       6. The method according to  claim 3  further comprising:
 sending an error message to the wireless audio device, if the codec identifier fails to correspond to an audio gateway codec available at the audio terminal; and 
 re-performing the exchanging step. 
 
     
     
       7. The method according to  claim 1  wherein the service class is Voice over Audio/Video Distribution Transport Protocol. 
     
     
       8. The method according to  claim 7  wherein the establishing comprises:
 creating a Hands-Free Profile Radio Frequency Communication protocol connection; 
 opening an Audio/Video Distribution Transport Protocol signaling channel; and 
 configuring a first Audio/Video Distribution Transport Protocol media transport channel between the audio terminal and the wireless audio device. 
 
     
     
       9. The method according to  claim 8  further comprising:
 configuring a second Audio/Video Distribution Transport Protocol media transport channel between the wireless audio device and the audio terminal. 
 
     
     
       10. The method according to  claim 1  wherein the service class is Voice over Bluetooth Network Encapsulation Protocol. 
     
     
       11. The method according to  claim 10  wherein establishing comprises:
 creating a Hands-Free Profile Radio Frequency Communication protocol connection; 
 establishing a Bluetooth Network Encapsulation Protocol link between the wireless audio device and the audio terminal. 
 
     
     
       12. The method according to  claim 1  further comprising:
 receiving a trigger at the audio terminal requesting establishment of a full-duplex audio connection over an asynchronous Bluetooth link with the wireless audio device. 
 
     
     
       13. The method according to  claim 12  further comprising:
 selecting a codec, after the exchanging step. 
 
     
     
       14. The method according to  claim 13  further comprising:
 selecting a service class, after the exchanging step. 
 
     
     
       15. The method according to  claim 14  further comprising:
 transmitting a service class identifier corresponding to the service class. 
 
     
     
       16. The method according to  claim 14  further comprising:
 transmitting a service class identifier corresponding to the service class; and 
 transmitting a codec identifier corresponding to the codec. 
 
     
     
       17. A method for a hands-free unit to establish a full-duplex audio connection over an asynchronous Bluetooth link with an audio gateway comprising:
 transmitting information regarding hands-free unit supported service classes and codecs; 
 receiving information regarding audio gateway supported service classes and codecs from an audio gateway; 
 selecting a hands-free unit service class and a hands-free unit codec based on the information regarding hands-free unit supported service classes and codecs and the information regarding audio gateway supported service classes and codecs; 
 transmitting a hands-free unit service class identifier corresponding to the hands-free unit service class and a hands-free unit codec identifier corresponding to the hands-free unit codec; 
 receiving an acknowledgement message from the audio gateway; and 
 establishing an asynchronous audio connection with the audio gateway using the hands-free unit service class and the hands-free unit codec. 
 
     
     
       18. The method according to  claim 17  wherein the service class is Voice over Audio/Video Distribution Transport Protocol. 
     
     
       19. The method according to  claim 17  wherein the service class is Voice over Bluetooth Network Encapsulation Protocol. 
     
     
       20. The method according to  claim 17  further comprising:
 re-performing service discovery if an error message is received. 
 
     
     
       21. The method according to  claim 17  further comprising:
 re-performing service discovery if no acknowledgement message is received during a timeout period.